The present invention relates to a conveyor roller whose cylindrical body is made from a moldable polymer concrete material. The invention further relates to a conveyor roller provided with at least one encapsulated labyrinth seal mounted on a shaft of the roller inside each end of the roller body such that the seal is contained within the roller body between a bearing of the roller and an exterior side of the roller body.
Conveyor rollers are conventionally made of steel, that is the conventional roller comprises a cylindrical steel tube which rotates on a shaft by means of bearings. The present invention relates to a conveyor roller made of a moldable polymer concrete or resin concrete material which has many advantages over steel or metal constructions. A roller constructed of a polymer concrete material can be more shock resistant, more resistant to acids and caustic substances from low pH to high pH, and easier to manufacture than a roller constructed of steel or other metal materials.
A problem arising with conventional conveyor rollers, however, is that the bearings of the roller become contaminated with foreign matter (such as dust particles) originating from the environment in which the roller operates. Contamination of the roller bearings is the primary reason for roller breakdown. Contamination will damage a bearing due to mechanical wear on the bearing caused by the interaction of the foreign particulate matter and the bearing movements, and due to chemical wear, such as rusting. A damaged bearing can decrease operating efficiency, require replacement, or lock up causing possible damage to a conveyor belt. It is known to the inventors to make a conveyor roller using a polymer concrete, however, the known roller has no labyrinth seal provided inside the roller body to protect the bearings against contamination.